SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fca66e1df9c835774cc36c17fa7b49c72bf5f7fbd2fd0dcd19515c43496e18f' 
  AND token = '/BbpQM+iGwYuA5wA52mUEizFpGJ/ylMcOQ/Twl2J9ZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}